High performance rechargeable batteries, such as Li-ion batteries, are widely used to power electric vehicles. One operating characteristic that affects the performance of such batteries is the pressure experienced by the battery cells within a battery assembly. Some battery assemblies include a stack of battery cells compressed using a structure that maintains a relatively constant pressure on the battery cells within the stack. In the case of pouch cells with no metal enclosure, this also provides the required support for the cell. This pressure is selected to achieve optimum performance of the cells and is typically specified by the manufacturer of the cells. For example, for some cells with a capacity of around 14-20 Ah, the recommended pressure is about 35-50 kPa. In some cases, the pressure specified by the manufacturer is designed to prevent delamination of the cells during use.